Tube turner for plug mills



June 30,1959 G. E. MOORE yIUBE TURNER FOR PLUG MILLS 5 Sheets-Sheet 1 ATTORNEYS Filed June 9, 1955 June 30, 1959 G. E. MOORE TUBE TURNER FOR lPLUG MILLS 3 Sheets-Sheet 2 Filed June 9, 19,55

INVENTOR. GEORGE E. MOORE )VM/vw* ATTORNEYS June 30, 1959 G. E. MOORE I' 2,892,366

TUBE TURNER FOR VPLUG MILLS Filed June 9, 1955 3 Sheets-Sheet 3 FIG. 8

7 4 48 /52 48\ 69 74' ///1// l 74 70 1N V EN TOR.

M Q N GEORGE E. MOORE 75/ se BY M om I 67- /-7| ,73 73a 73 72- 77 VMM d L A l 767 /M v 66 ATTORNEYS United Staffe Patent TUBE TURNER FOR PLUG MILLS Application June 9, 1955, Serial No.v 514,273 l 2 claims. (ci. zio- 11) 'This invention relates to apparatus for the manufacture of seamless tubing and more particularly to apparatus released from the tube so that the 2,892,365 Patented Junev 30, 1959 p'ass'es through the plug mill. In the preferred fori' of my invention this object is carried out by providing a pair of grippers or tongs which are actuated to grasp the tube upon its being returned to the receiving table, are then rotated substantially about the axis of the tube to rotate the tube through approximately 90, and are then tube can be repassed through the mill. l f A preferred form of the invention is illustrated in the accompanying drawing,- in which l Figure 1 is a side elevational view of a receiving table t embodying my invention showing the associated plug mill for turning tubes about their own axis in a tube rolling =mill of the type known as a plug mill.

Plug mills are used extensively in the manufacture of :seamless tubing and comprise a two-high.ro1l..stand hav- :ing grooved working rolls for rolling the tubing; a mandrel bar for supporting a mandrel or plug in the pass of 'the working rolls; a pair of stripping rolls, which are 'grooved to correspond to the working rolls, for removing -fthe tube from the mandrel; a receiving table `embodying a trough for supporting a tube on the entering side of the rolls, and a pusher for pushing the tube into the roll pass. In the conventional operation of aplug mill, a reheated pierced billet is deposited in the trough of the receiving table, the pusher shoves the billet into the pass of the working rolls over the mandrel, and the revolving work rolls draw the tube rapidly over the mandrel reducing the diameter and wall thickness of the tube andelongating it. As soon as the tube has passed through the working rolls, the mandrel is removed from the mandrel rod, the working rolls are separated, and the .stripper rolls are engaged with the tube and move the tube rapidly in the opposite direction oli of theV mandrel rod, through the space between the working rolls and into the trough ofthe receiving table. Y p V p The grooves inthe working rolls are not semi-circular but are flared or oval in order to preventthe edges ofthe grooves from damaging the tubej as -it passes through vthe l work rolls. Accordingly, after the iirst pass through the mill Ithe tube is Yslightly oval with i-ts major axis in a horizontal plane and with greater wal1. thickness in the regions at the ends o f major axis than` in the regions at the ends of the minoraxis; it is therefore necessary Vto rotate the tube 90 aboutits longitudinal axis and pass it through the plug mill again in orderto make it approximately round. and with a. substantially uniform Wall thickness throughout.

Accordingly, in ordinary practice, after the tube has I been subjected to `the first rpass through .the mill, an operator grasps the tube with a pair of ton/gs and rotates it through ap} roximatelyA 90. Then the pusher is actuated to push the -tube into the roll pass again land the rolling and stripping cycle is' repeated. The tube, which is still at a bright redheat, is thendischarged from the vreceiving table and progressed to further operations. i The operator who hasthe task of rotating the tub'e p 4the pass of the working rolls.

afterthe irst pass through the mill must work between the working roll stand andthe end of the receivingtable, 'i

a location that is extremely hot and not without hazard. 'The conditions under which the operator must work are so severe that ordinarily an operator is expected to work only 15 minutes out of eachV hour and it is therefore necessary to have fourfmen just to' rotate the tubes Vbetween the rst and second passes through the plug mill. The objectof the present invention is to providea'n effective mechanism `for grasping and turning the tube y as it rests in'the trough `of the receiving table between side of the receiving table.

in vertical section.

Figure 2 is a plan view of the apparatus shown in Figure l. l

Figure 3 is a transverse sectional View illustrating the tube turning mechanism, the section being on an enlarged scale and taken as indicated by -lines 3-3 of Figures l and 2.

Figure 4 is a sectional detail on an enlarged scale taken as indicated by line 4 4 of Figure 3. v

Figure 5 is a sectional detail illustrating the cylinder for actuating the gripping tongs and taken as indicated by line 5 5 of Figure 3.

Figure 6 is a View similar to Figure 3 but on a larger scale and with some of the parts broken away.

Figure 7 is a plan view of the tube turning mechanism shown in-Figure 3, and

Figure 8 is a sectional detail taken as indicated by line 8--8 of Figure 3.

Referring particularly lto Figures 1 and 2 of the drawings, the invention is illustrated as it may be adapted for use with a plug mill indicated in general at 10 and having upper and lower working rolls 11 and 12 mounted in roll stand 13. AImmediately behind the working rolls 11 and 12 are stripper rolls 14 and 15 Which are mounted in-a suitable roll stand 16. As shown best in Figure 2, the working rolls 11 and 12 are conventionally provided with a plurality of slightly oval grooves 18, so that the mill can roll tubes ofdilferent diameters, and the stripper rolls are also grooved, as indicated at 19 in Figure l, to correspond with the main rolls. A water cooled mandrel bar l21 is lsupported Vto project between the rolls and support a mandrel or plug 22 in the pass of Ithe working rolls 11 and 12.

As indicated by the arrows, Figure l, the working rolls are driven so as to draw the tube over the mandrel and bar and the stripper rolls are driven in the opposite direction so as to return the tube to the working table. 'I'he apparatus is so arranged that only one pair of rolls may be in contact with the tube at any given time.

Work pieces are supplied to the working rolls and received from the stripping rolls by a receiving table indicated generally at 24. The table 24 includes a trough 25 for guiding the tube and a pusher 26 actuated by a uid pressure cylinder mechanism 27 for pushing the tube into The trough preferably is made up of a plurality of sections of longitudinally ex,- .tending strips 82. The entire receiving table is supported .upon a frame work of longitudinally extending beams 29a, 29h, 29C, and 29d (Figure 3), the lower pair of which arev supported on pairs of longitudinally spaced wheels 30 (only one pair being shown in the drawing) which run on transverse rails 30a. Positioning mecha- ,nism 31 moves the table on the rails so that the trough 25 may be aligned selectively with any the working rolls.

In` order to supply tubes to the mill, a plurality, of 4skids 32 are secured to and extend outwardly from one The skids are adapted to receive the hot tubes which are brought to the receiving table for working in the mill. A plurality vof stops 33,

of the grooves 18 of downwardly rotatable by shaft 34, are disposed along the table on the same side as the skids 32 and control the entry of the tubes, by gravity feed, into the trough 25. Fluidpressure cylinder 35 actuates shaft 34. A plurality of discharge arms 36,'vupwardly rotatable by theshaft 37, are disposed along the other side of the receiving table. The arms 36 normally underlie the trough 25 between the sections 2S and are adapted to lift the tubes out of the trough and discharge them from the table and mill after they have been worked. The shaft 37 and arms 36 are actuated by uid pressure cylinder 38.

`All of the elements heretofore described may be of conventional construction and per se `form Vno -part of the-present invention.

In the conventional operation of a plug mill constructed or described above, a hot tube is brought to the mill anddeposited upon the skids 32 where it remains,.resting against the stops 33, until the same are rotated downwardly to permit the tube to roll into the trough 25. The tube is then pushed into the pass of the working rolls, which are in working position, and is drawn over the mandrel by the rolls; the working rolls are then separated and the stripper rolls engaged with the tube to return it to the table. An operator stationed between the working rolls and the end of the receiving table then grasps the tube with tongs and rotates it about 90; thereafter, it is again passed through the mill and returned to the trough. The cylinder 38 is then actuated to rotate the arms 36upwardly and discharge the tube frornthe table.

According to the present invention, a mechanism is incorporated inthe apparatus for rotating the tubes about their own axis for approximately 90 between successive passes through the working rolls 11 and 12.

The `apparatus forturning the tubes is preferably disposed near the end of the receiving table adjacent the milllrolls and is indicated in 'general at'45. As shown particularly in Figures 3 and 6, the tube turning'apparatus comprises a pair of tongs or grippers for 'grasping the tube, which are mounted on a carriage, and means to move the carriage along an arcuate track land thereby turn the tube.

yMore particularly, the preferred embodiment of my invention comprises a pair of gripper arms 47 and 48 having opposed gripper jaws 49 and 50 which are adapted to Lengage -and grasp a tube lying in-the trough. The arms 147 .and 48 extend laterally away from the axis of the tube and the ends of the arms 47 and 48 remote'from vthe jaws 4are pivotally supported for pivotal movement about axes vparallel to the axis of the tube as at 51 and 52in a carriage v54 and are also geared together as'by teeth 55 and 56'so that the jaws 49 and 50 are constrained to rotate about the pivots 51 and 52 in lequall angular amounts and in opposite directions.

4The jaws are moved toward and away from eachother orinto-and out of engagement with tubeby'means kof'a double acting fluid pressure cylinder and piston mechanisrn'which'is mounted between the arms 47 and 48, see 'Figures 3, 5 and. The'cylinder 58 is mounted on'arm lv47by means of trunnions 59 and the pistonrod 60 is 'secured to arm 48 by wrist pin 61. Fluid under pressure is'supplied to the cylinder through appropriate conduits andthe arrangement is such that admission of uid on the sideof the piston nearer the arm 48 will force the piston :further into the cylinder and will move the arms 47 and Y48a11d jaws 49 and 50 toward each other about the pivots 51 and52 so as to cause the jaws to grasp and .clamp the tube, whereas admission of fluid on the other "side of the piston will push the'piston further out of the .cylinder and move the arms and jaws apart, releasing the tube.

Preferably, the `jaws 49 and 50 are detachable from the arms 47 and 48 so that jaws of appropriate size for -"the tubes being worked may be used.

-'The carriage Y54 provides means for rotating or turn- 4 ing the tube 90 about its own axis once it has been grasped by the jaws. To this end, I provide wheels or rollers 65 at both ends of the carriage 54 and an arcuate track indicated generally at 66 on which the wheels 65 operate. The track 66 is supported by the table frame members 29a and 29b and preferably has its center coincident with the axis ofV an average sized tube, as determined by the capacity of the^mill, lying'in the trough 25.

As shown particularly in Figures 4 and 8, the track preferably comprises vertical outer arcuate webs 67 and 68 which support 'arcuate'ilange members 69 and 70, and inner vertical track members 71 and 72 which inturn are secured vto .an arcuate plate 73 having openings 73a therein. The wheels or rollers 65 are retained between and roll or traveluponthe `oppositely ldisposed surfaces 74 of the flange members 69 and 70, and 75 of the inner track members 71 and 72.

.Aplurality yof arcuately spacedsupports 76 and 77 support'the inner trackmembers 71 and 72 and the adjacentrwebs 67 'and 68 respectively in proper'spaced relation. The spaces between the supports, and the openings 73a 'rpermit the .discharge of scale and dirt that might otherwiseaaccumulate insidevof the box-like track structure. .Plates 80.at the ends of the track, vertical plates 82 andiplates'SBform rigid channel structures at each end ofrthetrack. Pilates and '.82 arefor stiffening the structure. The .travel of .the'trolley is limited by the strokeofthe cylinder 92. The track 66 is conveniently of :welded construction as indicated. yThe plates '83 are welded fto .the .webs 67 and 68sand are bolted to the upper Aflanges of beams 29a and 29bto support the track.

'In 'order yto Iprovide rfor movement of the 4carriage alongfthe track, Iafpin 84 (see Figures 6, 7 and 8) is secured kto theframe members'85 yof the carriage 54 and projects beyond the carriage oneither side thereof. Connectingrods 'are pivotallysecured to the ends of pin 84faud these, .'inturn, -are pivotally connected to lever arms87 mounted-*on shaft 88. Shaft 88'is supported in a-suitable bracket 89 onthe entry side of the delivery table vand is rotated by a crank arm 90 which is actuated byy the piston rod 91-of a double acting fluid pressure cylinder and piston -92 mounted in trunnions 93 on bracket 89. Movement of the piston out of the cylinder causes'the connecting rods 86 to pull the carriage 54 along the tracks 66 from the position shown in full lines inFigure 6 tothe position shown in broken lines in Figure 16. The carriage vand the gripper jaws are thus rotated substantially 90 `about 'an axis disposed within the trough 25and substantially coincident with the axis of thetube, and a tubeengaged by the gripper jaws is likewise rotated substantially 90, or oner quarter turn.

*The'operation of a, plug milll embodying vapreferred form of Vmy invention is lsubstantially the same as that I'described'aboveexcept'for the tube turning mechanisms. The cylinder 58 4is actuated to openor separate the jaws T49 and 50and keep'them open-when the tube isdelivered -to the trough 25 from the skids 32 and when the tube is returnedto the .trough after `a pass through the'mill. After'therst pass is completed and the tube has been returned to the. receiving table,l the cylinder 58 is actuated to move the arms'47 and 48 towardeach other and `causethe jaws"49 and 50 to grip'the tube. With the tube'thus gripped, the cylinder 92 is actuated to move "the carriage 54 along'thetrack through 90 degrees of arc thereby rotating 'the tube in the manner hereinbefore `described. The cylinder 58 is then actuated to separate lthejaws and release the tube, whereupon .the tube is again passed through the rolls and returned to the receiving .tableffor 'discharge therefrom.

'As`it normally .does not matter whether a tube is rotated 90 to the left or right, between successive ipassesthroughthe mill, the carriage may be kept in its new yposition until after 'the next tubehas completed its first passfthrough the mill and the apparatus is .then

actuated'to turn the next tube in the opposite direction.

However, if it is desired to rotate each tube in the same direction, the carriage may be returned to its initial position each time a turn is completed.

Although I have illustrated and described a specific form of my invention, various changes and modifications thereto will occur to those skilled in the art, all within the precepts of my invention, and I do not care to be limited in the scope of my patent to the precise embodiments herein particularly illustrated and described.

I claim:

1. In apparatus of the type described, guide means adapted to support a tube, an arcuate track having its center substantially coincident with the axis of a tube supported on said guide means, a carriage mounted on said track, tube grasping means carried by said carriage, said tube grasping means comprising a pair of arms pivotally mounted on said carriage and lbeing geared together at one end and having opposed jaws at the other end adapted to engage a tube supported on said guide means and a `fluid pressure cylinder and piston means acting between said arms to move said jaws toward and away from each other, and a uid pressure motor for moving said carriage on said arcuate track thereby to rotate a tube grasped by said jaws substantially about its own axis.

2. In apparatus of the type described, guide means adapted to support a tube, an arcuate track having its center substantially coincident with the axis of a tube supported on said guide means, a carriage mounted on said track, tube grasping means carried by said carriage, said tube grasping means comprising a pair of arms pivotally mounted on said carriage and being geared together at one end and having opposed jaws adapted to engage a tube supported on said guide at the other end and power means for moving said jaws toward and away from each other, and power means for moving said carriage on said arcuate track.

References Cited in the le of this patent UNITED STATES PATENTS 763,307 Mills June 21, 1904 1,721,283 Ruth July 16, 1929 1,762,427 Stiefel June 10, 1930 1,833,330 Palmgren Nov. 24, 1931 1,928,811 Burns Oct. 3, 1933 2,183,557 Ferm Dec. 19, 1939 2,450,934 Calhoun Oct. 12, 1948 2,573,410 Dearborn Oct. 20, 1951 2,627,109 Bock Feb. 3, 1953 2,632,346 Peterson Mar. 24, 1953 2,708,378 Smith May 17, 1955 2,837,945 Griffiths June 10, 1958 

